ICD-10 Code K51.8 – Other ulcerative colitis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code K51.8 – Other ulcerative colitis
What it is
K51.8 identifies ulcerative colitis that does not fit the more specific ulcerative colitis subtypes. Use it when documentation confirms ulcerative colitis, but the record does not specify a different category.
Clinical signs
Typical findings include chronic inflammatory bowel disease symptoms such as diarrhea, rectal bleeding, abdominal pain, and urgency. Clinical features vary; refer to documentation.
When to use this code
Use K51.8 when the provider documents ulcerative colitis and the type is described as other or not otherwise specified within this category. It also fits when the chart confirms ulcerative colitis but does not support a more specific code. Check documentation for extent and subtype before assigning a broader code.
Do not use for
Do not use this code for Crohn disease, infectious colitis, or nonspecific diarrhea without a diagnosis of ulcerative colitis. Do not use a more specific ulcerative colitis code if the record clearly identifies the disease subtype.
Coding tip
If the note is vague, query for the exact ulcerative colitis subtype before defaulting to K51.8.